This example implements a custom cell edit form and validates values once a user entered in that form.
This example uses the DataFormView control to implement the edit form and handles the DataFormView's ValidateForm event to validate input values once a user saves changes in the edit form.
Specify the DetailEditFormTemplate property to define the custom edit form content. To invoke the edit form on a row tap, bind the RowDoubleTapCommand property to the ShowDetailEditForm command.